RECORD: Darwin, C. R. 1878.01.15-21. Ipomoea or Pharbitis nil. CUL-DAR209.4.185-186. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 9.2022. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR209.4 contains materials for Darwin's book Movement in plants (1880).


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1878

Ipomoea or Pharbitis nil

(observed on account of doubt whether Cot go on sinking late at night.)

Young seedling with Cots. observed under skylight. [sketch]

Jan 15th Cot fell rose from 8° a.m. to 12°; by 1° had fallen & continued till 10° 30' falling considerably: was then placed under Bell-glass in my Bed-room, continued to fall as observed at 11° 30' P.m, 1° 30' a.m (in night of 16th), 3° 30', 6° 30' — Was then removed to under skylight & at 8° 25' had risen a little, so turning point was between 6° 30' & 8° 25 a.m. (Used) Nevertheless it is doubtful whether trustworthy as seedling was poorly illuminated during all the 15th under the skylight, & temp, was low, only 15° to 15 1/2 C. After 8° 25 on the 16th continued rising but very little till 12°, by which time it began to fall & so continued all rest of day & the night; but the move movement was very small, as if plant paralysed.—

[in margin:] Apex of leaf 6 inches from vertical glass

Certainly seem to begin falling about noon, Whenever the rising rising may commence.— O

In text fall did not commence till 4° P.m Light another in obscure place, began descending at noon

(1 (2

Ipomoea nil

(Used)

(A new fine vigorous seedling with Hypocotyl 2 inches high secured to a little stick was observed kept all day in Hothouse so as to be well illuminated & placed at 4° 20' under skylight. (Temp. 19 3/4 C.) (see Tracing) & Cot, continued to fall till 10° 15, when plant was carried into my bed-room & placed under Bell-glass & movement traced twice during night. — Tracing joined to last; but the Tracing on following day (21st) (Temp. 19 1/2 C) not joined for too complex. —

By 12° 30' in night had risen a little & by 3° 45' considerably; but by 6° 12' a.m had fallen greatly.— Was then transferred to skylight & was observed from 12° 30' to 6° every 1/2 Hour ; & at other times about every Hour— The figure wd have been much mor complex, if observed half-Hourly for whole day. The course pursued wonderfully complex, & moreover very rapid: went up & down about 13 times between 6° 20' a.m & 10° 30' P.m

This is very interesting case, as shows that great & rapid & complex movement not connected with sleep.— Late in evening went far down this seem general rule, & rises during night,  apparently — between 10 & 11° after between 11 & 12° P.m. ─ I do not understand why course was so simple on evening of 20th The important point is falling till at least between 10° & near 11° P.m.

[in margin:] Apex of leaf only 4 1/8 from glass — approximately Horizontal Length of Cot & petiole. to tip of cot 1.6 inch.


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 27 September, 2022